/*
 * Copyright (c) 2021, Red Hat, Inc. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package org.openjdk.jcstress.os.topology;

import org.openjdk.jcstress.os.NodeType;
import org.openjdk.jcstress.vm.VMSupport;

import java.io.PrintStream;
import java.util.Collection;

public interface Topology {

    static Topology get() {
        if (VMSupport.isLinux()) {
            // Try to parse sysfs
            try {
                return new LinuxSysfsTopology();
            } catch (TopologyParseException tpe) {
                // No dice...
            }

            // Try to parse /proc/cpuinfo
            // (both Linux, and Windows can show this)
            try {
                return new LinuxProcfsTopology();
            } catch (TopologyParseException tpe) {
                // No dice...
            }
        }

        try {
            return new FallbackTopology();
        } catch (TopologyParseException tpe) {
            // Cannot actually happen.
            throw new IllegalStateException("Internal error");
        }
    }

    void printStatus(PrintStream pw);

    boolean trustworthy();

    int threadsPerCore();
    int coresPerNode();
    int nodesPerSystem();
    int totalThreads();
    int totalCores();

    Collection<Integer> coreThreads(int coreId);
    Collection<Integer> nodeCores(int nodeId);

    int threadToCore(int threadId);
    int threadToNode(int threadId);
    int coreToNode(int coreId);

    int threadToRealCPU(int threadId);

    NodeType nodeType();

}
